Microstructural Control of a Zn-22Al Alloy by Rolling Process

The Zn-22Al alloy with fine-equi-axed has been well known as a typical superplastic metallic material [1]. In the present study, The Zn-22Al alloy ingot of 20mm thickness was homogenized, either air-cooled or water-quenched, and then hot-rolled to a thickness of 2mm. Microstractural observation, showed that in the air-cooled specimens lammellar microstructure was formed after homogenization, and become fragmented to fine-grained microstructure as the hot rolling process proceeded. In the water-quenched specimens, equi-axed fine-grained microstructure with grain size under 2.1μm was attained and maintained throughout the hot rolling process.